Porifera Platyhelminthes Cnideria Mollusca Nematoda Arthropoda Annelida Echinodermata

Porifera Platyhelminthes Cnideria Mollusca Nematoda Arthropoda Annelida Echinodermata pseudocoelom segmentation acoelom Protostome radial symmetry no true tissues Deuterostomes bilateral symmetry true tissue Ancestral Protist Chordata

Animals Vertebrates Mammals Fish Reptiles Amphibians Birds Invertebrates Cnidarians Flatworms True worms Molluscs Echinoderms Arthropods

Phylum Porifera Class Hexactinellida Class Calcaria Purple and yellow tube sponge Class Desmospongia Boring sponge Class Sclerospongia

Phylum Cnidaria Class Hydrozoa Hydra Portuguese Man-Of-War Stinging Limu Fire Coral Class Scyphozoa True jellyfish Class Cubozoa Box jellies Sea wasps Class Anthozoa Corals Anemones

Phylum Annelida Class Oligochaeta earthworms Class Polychaeta marine worms Class Hirudinea leaches

Phylum Mollusca Class Polyplacophora chitons Class Gastropoda Snails nudibranchs More than 500, 000 known species Class Bivalvia clams Class Cephalopoda Squid Octopus Nautilus

Phylum Arthropoda Subphylum trilobita trilobites Subphylum Uniramia Chelicerata Insects Horseshoe crab Millipedes Sea spiders Centipede Subphylum spiders Beetles Crustacea Crabs Krill Shrimp Lobster Ispod amphipod

Phylum Echinodermata Class Astroidae Sea stars Class Ophiuroidae Brittle stars Class Echinoidae Sea urchins Class Crinoidae Crinoids Class Holothuroidae Sea cucumbers

Phylum Chordata Subphylum Urochordata tunicates Subphylum Cephalochordata lancets Subphylum Vertebrata Agnathans Fish Sharks tetrapods

Subphylum Vertebrata Class Agnatha Class Retile Class Chondrichthyes Class Osteichthyes Class Amphibian Class Aves Class Mammalia